Casting apparatus



n March 21, 1939.

H. E. MCWANE 2,151,131

CASTING APPARATUS F'iled OC'. l5, 1934 @A Wwymp Patented Mar. 21, 1939UNITED STATES PATENT OFFICE 3 Claims.

This invention relates to casting, and more particularly has referenceto a mold and core therefor. The present device is related in some:respects to the invention disclosed in my cepending application SerialNo. 748,124 led October Certain difliculties have been encountered inthe use of cores of the prior art. As is well known, ra kcasting duringsolidication and cooling Ashrinks to a certain extent, and, particularlyif this is impeded, stresses and strains are set up inthe casting 'whichfrequently result in cracks `and other imperfections in the finishedcasting. A core that is not free to move during such period of shrinkageis of course to be avoided, but even in those cores which are freelymovable there reside certain objections. These cores are not usually ofthe permanent type, thus necessitating the formation of a new core foreach operation. Furthermore, the prior cores, whether permanent ordestructible, require the accurate positioning of the core in the moldcavity, for .otherwise the apertures or recesses formed by the cores inthe finished casting will not be uniformly placed. The accuracy of suchpositioning depends upon the skill of the operator, and appreciablelosses have resulted from careless placing of the core in the moldcavity.

To overcome the above disadvantages is one of the objects of myinvention.

Another object of my invention is to provide va. core that isinexpensive to manufacture and which is capable of operation over a longperiod of time.

vide a movable core which thereby permits of the fr'ee shrinkage of thecasting, and which is rquickly returned to a uniform position in themold cavity for the succeeding pouring operation.

To accomplish the above and other important objects as will more fullyappear herein, my in- Vention in general comprises a core that may bemoved .and which permits the free shrinkage of the casting, inassociation with means whereby the core may be positively and accuratelyreturned to the desired position for a succeeding pouring operation.

To aid in understanding my invention, reference is made to theaccompanying drawing which discloses one specific embodiment, it beingdistinctly understood, however, that various modications may be madetherein without exceeding the scope of my invention as defined by theappended claims.

Yet another object of my invention is to pro- In the drawing, in whichcorresponding numerals refer lto the same parts:

Figure 1 is a top view of a mold section of my invention partly in planand partly cut away.

Figure 2 is a sectional view along the line 2--2 of Figl, looking in thedirection of the arrows, and showingthe core in extended position.

Figure 8 is a fragmentary view of Fig. 2, showing the core in retractedposition.

Figure 4 isa sectional view along the line 4 4 of Fig. 2, looking in thedirection of the arrows.

Figure 5 is a sectional view along the line 5-5 of Fig. 2, looking inthe direction of the arrows.

While my invention is by no means limited thereto, I shall describe itin connection with the casting of a plate-like member in which it isdesired to provide apertures, .such as, for instance, a plow platecontaining bolt holes.

In Fig. 1 I have shown the lower half I of a mold in which a pair ofcastings may be cast. The section I is provided with mold cavities 2which may be filled through main runner 3 and branches 4. Risers 5 maybe provided as necessary.

Cores designated generally 6 -are arranged in the cavity for the purposeof forming bolt holes or other apertures or recesses therein. If roundor conical bolt holes are desired, a rib "I may be provided upon thecore in .order to provide a channel in the bolt hole which is adapted toreceive a rib upon the .bolt head.

In Fig. 2 I have shown the core of frustoconical shape, but it will ofcourse be appreciated that it may be frusto-pyramidal or certain othershapes. The tcp of the core 8 is preferably flat, and, when it isdesired to have an aperture extending through the casting, the top 8 isadapted to bear against the upper half El of the mold.

When in extended position the core is seated in a tapered channel IIwhich opens into the mold cavity. It will be appreciated that anaccurate seating of the core at a uniform place in the mold is thereforealways assured.

Secured to the Abase of each core is a stem `I2 which is preferably,though not necessarily, cylindrical. As best shown in Fig. 4, the stemI2 is provided with a transverse slot I3. As also shown in Fig. 4, anarm I4 is adapted to extend through the slot I3. The arm I4 is providedwith a cammed slot I5 which is adapted to receive a pin I6 extendingthrough the stem I2.

It will therefore be appreciated that longitudinal movement of arm I4raises or lowers the core 6.

The lower half I of the mold is preferably made up of a main section I'Iin which the mold cavity 2 is formed and a lower section I8 adapted tobe secured to the body portion II by screws I9 or other suitablefastening means.

A channel 2| is formed in the body portion and is adapted to receive andpermit the sliding therein of arm I4. As best shown in Fig. l, Ihavedisclosed a plurality of cores 6 for which I provide a common operatingmeans to raise and lower the core. In this ligure it will be noted thatall of the arms I4 are joined to a single cross bar 22 which istransversely reciprocable in a channel 23 formed in the body portion I'Iof the mold. A single operating arm 24 is joined to the cross bar 22,and is provided at its end with a ring 25, or other suitable means forengagement by the operator. It will of course be appreciated that thechannels 2| and 23 are formed to provide suilicient clearance to permitof the ready sliding of the arm. I4 and cross bar 22.

While I have shown a single operating means for all of the cores, it isof course to be appreciated that each core may have its independentoperating means if such should be desired for any reason.

The lower portion I8 of mold section I is provided with a channel 26adapted to receive that part of stem I2 extending below the arm I4. Thestern I2 is free to reciprocate in channel 26 upon extension orrecession of the core, and the channel 26 therefore serves as a guidefor the core and maintains the latter aligned at all times.

The operation of my device is believed to be obvious from thedescription. Prior to the pouring operation the arm 24 is pushed in,which in turn pushes in each of the arms I4. 'Ihe cores 6 are therebyraised into their extended position in seat II by virtue of cammed slotI5 and the pin I6, whichrides therein. As heretofore stated, in thisposition the top 81 of the core rests against the upper half 9 of themold. The molten metal is then poured into the mold cavity and fills thesame except at those points at which the cores are located. Uponcooling, the metal solidies and starts to shrink. As is well known, thisshrinkage is accompanied by a withdrawal of the casting from the sidewalls of the cavity and by corresponding displacement of the apertureswhich were formed by the cores.

My invention is designed for the purpose of permitting such freedisplacement of the apertures. Immediately upon solidication of thecasting, but prior to any shrinkage thereof, the arm 24 is pulledoutwardly by the operator, and the cam slot I5 and pin It cause the coreB to be withdrawn into the channel II so that the top 8 of the core isush with the bottom of the Ymold cavity. When the core is in thisposition there can, of course, be unlimited. shrinkage without anydanger of the casting contacting with the core. It should be pointed outthat any skilled and practiced operator can accurately estimate themoment at which the casting begins to shrink and can therefore operatethe arm 24 accordingly.

After the casting has been removed, the cores are reset by merelypushing the arm 24 in. Y

The advantages of my invention are obvious.

consequently each casting is assured of havingV the necessary aperturesor recesses at the exact positions desired.

I have referred herein to a few modications that may be made in myinvention, but it will of course be obvious that various additionalchanges may be made without exceeding the scope of my invention asdefined in the appended claims.

I claim:

l. A casting apparatus comprising a mold, aV

channel communicating with the mold cavity, a core slidable in thechannel and adapted to extend therefrom into the mold cavity, a taperedaoY seat for the core in said channel to determine f the position of thecore inthe cavity, an arm reciprocable at right angles to the channeland provided with a'cammed slot, a pin extending from the core throughsaid slot, and means to reciprocate the arm to thereby slide the core inthe channel.

2. In a mold construction embodying cope and I drag members, a moldcavity in the drag,'a channel communicating with the mold cavity, a coreslidable in the cavity, atapered'seat for the core in said channel todetermine'the position of the core in the mold cavity, a second channelextending transversely of the drag member and in communication with saidrstchannel, and an arm reciprocable in said second channel with respectto the core and provided with means cooperating with the core to slidethe core in the first-mentioned channel.V

3. In a mold construction embodying cope and drag members, a mold cavityin the drag, a channel communicating with the mold cavity, a coreslidable in the cavity, a tapered seat for the core in said channel todetermine the position of the core in the mold cavity, a second channelextending transversely or" the drag member and in com- Vmunication withsaid iirst channel, andan arm reciprocable in said second channel withrespect to the core and provided with eammed means cooperating with thecore to slide the core in the rst-mentioned channel.

HENRY E. MCWANE.

